“Chemokines,” which take their name from chemotactic cytokines, are small secreted polypeptides that regulate movement of immune cells into tissues (Baggiolini et al. (1994) Adv. Immunol. 55:97-179; Oppenheim et al. (1991) Ann Rev. Immunol. 9:617-648). Chemokines are assigned to three different families based on the number and position of conserved cysteine residues (Van Coillie et al. (1999) Cytokine & Growth Factor Rev. 10:61-86). The a and b chemokines each contain four conserved cysteine residues. The first two cysteines of the a chemokines are separated by a single amino acid, thus containing a CXC amino acid motif. The first two conserved cysteines of the b chemokines are adjacent. Thus, the b chemokines are also known as C-C chemokines. By contrast, lymphotactin is the sole member of the third family of chemokines, and contains only the second and fourth conserved cysteine residues. Interestingly, in humans, a chemokines are all encoded by genes on chromosome 4, b chemokines are all encoded by genes on chromosome 17, and lymphotaxin is encoded by genes on chromosome 1.
The b-chemokines form a gradient that serves as a chemoattractant and potential proliferation signal for immune and other cells such as monocytes, macrophages, basophils, eosinophils, T lymphocytes and fibroblasts. MCP-1, MCP-2 and MCP-3 share sequence homology with one another at the amino acid level. Through interaction with specific receptors, termed C-C chemokine receptors (CCR) which are G-protein coupled, seven transmembrane receptors (Rossi and Zlotnik (2000) Ann. Rev. Immunol. 18:217-242), the b-chemokines regulate the expression of adhesion molecules on endothelial cells and thereby indirectly affect diapedesis and extravasation of immune cells from the circulation into tissues. There are ten different CCRs (CCR1 through CCR10). CCR2 acts as a receptor for MCP-1, MCP-2, MCP-3, and MCP-4 (Rossi and Zlotnik (2000) Ann. Rev. Immunol. 18:217-242). However, all human MCPs have been shown to interact with more than one receptor (Van Coillie et al. (1999) Cytokine & Growth Factor Rev. 10:61-86).
Human MCP-1, MCP-2 and MCP-3 all have chemotactic activity for a variety of cell types, including T lymphocytes and monocytes (Van Coillie et al. (1999) Cytokine & Growth Factor Rev. 10:61-86). Other shared functions of MCP-1, MCP-2, and MCP-3 include induction of N-acetyl b-D-glucosaminidase release, gelatinase B release, and granzyme A release which are believed to help the cells digest the extracellular matrix components necessary to enable them to migrate into tissues (Van Coillie et al. (1999) Cytokine & Growth Factor Rev. 10:61-86). In addition, MCP-1 and MCP-3 share various functions, such as induction of arachidonic acid release and stimulation of a respiratory burst (Van Coillie et al. (1999) Cytokine & Growth Factor Rev. 10:61-86).
MCP-1-specific antibodies have previously been described in the literature (WO 01/89582, WO 01/89565, Luo et al. (1994) J Immunol 153:3708-16; Traynor, et al (2002) J Immunol 168:4659-66). Certain MCP-1 antibodies have been described as binding MCP-1 and MCP-3, specifically the MRHAS domain of MCP-1 and MCP-3 (WO 95/09232). In addition, a human anti-MCP-1 antibody has also been described (WO 02/02640). There is a need in the art to identify antibodies which can be used to manipulate b-chemokines in general, and to specifically modulate the activity of multiple chemokines, e.g., MCP-1 and MCP-2 or MCP-3.